Which planet has the fastest winds in the Solar System?

Neptune has the fastest winds in the Solar System.

Wind speeds in Neptune’s atmosphere can reach about 2,100 kilometres per hour, faster than those measured on any other planet. The winds move through an atmosphere dominated by hydrogen and helium, with methane contributing to the planet’s blue appearance by absorbing red light.

Neptune receives far less sunlight than Earth because it orbits about 30 times farther from the Sun. Despite this weak solar heating, the planet radiates more energy than it receives. Scientists think Neptune’s internal heat helps drive its powerful atmospheric circulation, although the exact balance of processes remains an area of research.

Voyager 2 became the first spacecraft to visit Neptune, flying past the planet in 1989. It observed large storms, including the Great Dark Spot, though later observations showed that storm systems can form and disappear. Neptune’s winds are measured through cloud motion and atmospheric observations rather than by a solid surface wind gauge.